ASTM D8489-23e1

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: D8489 − 23
Standard Test Method for
Determination of Microplastics Particle and Fiber Size,
Distribution, Shape, and Concentration in Waters with High
to Low Suspended Solids Using a Dynamic Image Particle
Size and Shape Analyzer
This standard is issued under the fixed designation D8489; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Research report information was added to Section 14 editorially in May 2023.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the determination of microplas-
tic particle size distribution, shape characterization, and num- D883 Terminology Relating to Plastics
D1129 Terminology Relating to Water
ber concentration (particle counts) in sample extracts contain-
ing particles between 5 μm and 100 μm. Light is transmitted D1193 Specification for Reagent Water
D5847 Practice for Writing Quality Control Specifications
through a flow cell containing particles in liquid medium. The
particles create shadows as they pass through the field of vision for Standard Test Methods for Water Analysis
D8332 Practice for Collection of Water Samples with High,
of a camera, producing a multitude of images. The images are
then used to measure size, shape, and concentration. Medium, or Low Suspended Solids for Identification and
Quantification of Microplastic Particles and Fibers
1.2 This test method is used as a complementary technique
D8333 Practice for Preparation of Water Samples with High,
for microplastic particle and fiber polymer identification meth-
Medium, or Low Suspended Solids for Identification and
ods infrared microscopy and gas chromatography/mass spec-
Quantification of Microplastic Particles and Fibers Using
troscopy pyrolysis.
Raman Spectroscopy, IR Spectroscopy, or Pyrolysis-
1.3 This test method requires that samples are collected
GC/MS
according to Practice D8332 and prepared according to Prac-
E131 Terminology Relating to Molecular Spectroscopy
tice D8333 prior to use.
E1617 Practice for Reporting Particle Size Characterization
Data
1.4 Units—The values stated in SI units are to be regarded
E2651 Guide for Powder Particle Size Analysis
as standard. No other units of measurement are included in this
standard.
3. Terminology
1.5 This standard does not purport to address all of the
3.1 Definitions—For definitions of terms relating to this test
safety concerns, if any, associated with its use. It is the
method, refer to Terminologies D1129 and D883, and for
responsibility of the user of this standard to establish appro-
definitions of terms relating to molecular spectroscopy, refer to
priate safety, health, and environmental practices and deter-
Terminology E131.
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
3.2 Definitions of Terms Specific to This Standard:
dance with internationally recognized principles on standard-
3.2.1 microplastic, n—plastic particle less than 5 millime-
ization established in the Decision on Principles for the
ters (mm) in size.
Development of International Standards, Guides and Recom-
3.2.1.1 Discussion—The lower size of a plastic particle
mendations issued by the World Trade Organization Technical
determined as a microplastic is usually classified as 1 micron
Barriers to Trade (TBT) Committee.
(μm); however, the smaller size is limited by sample collection,
sample preparation, and analysis.
This test method is under the jurisdiction of ASTM Committee D19 on Water
and is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Organic Substances in Water. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved March 1, 2023. Published March 2023. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D8489-23E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D8489 − 23
4. Summary of Test Method techniques. Use infrared (IR) or Raman to identify and
quantitate microplastics greater than 100 μm.
4.1 This test method has been validated for microplastic
6.3 The solvents used in this test method may contain
particle size distribution, shape, and particle counts in sample
extracts containing particles between 5 μm and 100 μm. particles within the measurement range (size) of the method. In
addition, pipette tips may contain microparticles and require a
4.2 This test method is applicable to microplastic particles
preliminary rinse.
in municipal wastewaters, including sewage, treated effluent,
6.4 Other techniques (such as infrared microscopy and gas
the rivers in which they are discharged, ambient waters,
finished drinking water, and bottled water. chromatography/mass spectroscopy pyrolysis) are complemen-
tary and provide additional information, such as qualitative
4.3 Samples are collected by Practice D8332 and prepared
identification of individual polymers. Each of these test meth-
for analysis using Practice D8333.
ods uses samples collected and prepared by Practices D8332
4.4 This test method is applicable to common plastics
and D8333.
including polyethylene (high-density polyethylene (HDPE)
7. Apparatus
and low-density polyethylene (LDPE)), polypropylene (PP),
polyvinyl chloride (PVC), polyurethane (PUR), polyethylene
7.1 Refer to Guide E2651 for a detailed description of the
terephthalate (PET), and polystyrene (PS). The preliminary
Dynamic Digital Image Processing technique.
sample preparation by Practice D8333 removes most non-
7.1.1 Principle of Operation—A sample of particulate ma-
plastic material that would otherwise interfere.
terial is dispersed in a liquid stream. As the particles pass
through the measurement zone they are illuminated, either
4.5 The quantity and size distribution of microplastic par-
from front or back, to create two-dimensional projected images
ticles present in a sample are counted and theoretical estimates
that are captured by a digital camera and then analyzed using
can be inferred for the larger body of water.
image analysis software. Both size and shape information can
be obtained. Use an analyzer capable of determination of size
5. Significance and Use
distribution, shape, and particle counting in sizes of about 5 μm
5.1 Many microplastic particles enter the environment,
to 100 μm. It is desirable that the cell width is smaller than the
including ambient waters and drinking water supplies, via
depth of field.
wastewater sources resulting from both industrial processes
7.1.2 Specific Requirements:
and consumer products. The presence of high percentages of
7.1.2.1 The suspension must remain dispersed in the dilu-
organic particles, including cellulose material originating from
tion solvent.
toilet paper and chitin-based materials originating from insect
7.1.2.2 The rate of fall is slowed by the dilution solvent of
exoskeletons, makes visual identification and subsequent quan-
high viscosity used in this test method.
tification of microplastic particles in wastewater difficult.
8. Reagents and Materials
5.2 This test method, associated sampling Practice D8332,
and preparation Practice D8333 provide a standardized ap-
8.1 Purity of Reagents—Reagent-grade chemicals shall be
proach for the preparation of water and, particularly, wastewa-
used in all tests. Unless otherwise indicated, it is intended that
ter samples. The isolation of microplastic particles from
all reagents shall conform to the specifications of the Commit-
interfering contaminants by Practice D8333 enables positive
tee on Analytical Reagents of the American Chemical Society,
identification and, therefore, quantification of microplastic
where such specifications are available. Other grades may be
particles.
used provided they are pure enough to be used without
lessening the accuracy of the determination.
5.3 Using this test method, microplastic particles are char-
acterized in terms of size, shape, and quantity, allowing for the
8.2 Purity of Water—Unless otherwise indicated, references
enumeration of subsequent particle count for a given volume of
to water shall be understood to mean reagent water conforming
sample. The method does not provide qualitative identification
to Specification D1193.
of plastic composition.
8.3 Glycerin (sp.gr. 1.26)—Glycerin or glycerol 100 %
(C H O ).
3 8 3
6. Interferences
8.4 Methanol (sp.gr. 0.791)—Methanol (CH OH).
6.1 Because of the high percentage of organic matter,
8.5 Dilution Solvent—(1 + 1) methanol and glycerin.
cellulose, chitin, skin fragments, and clothing fibers present in
wastewater, the complete differentiation of microplastic par-
8.6 Standard Beads—Beads, 10 μm, 20 μm, 50 μm, and
ticles is impractical, if not impossible. Samples shall be
100 μm, are available from commercial suppliers. These are
collected using Practice D8332 and prepared using Practice
available with defined size distribution and an approximate
D8333 to facilitate identification of microplastic particles and
to make imaging analysis feasible. Practice D8333 digests all
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
non-plastic material.
Standard-Grade Reference Materials, American Chemical Society, Washington,
DC. For suggestions on the testing of reagents not listed by the American Chemical
6.2 This test method is used for particle sizes of 5 μm to
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
100 μm in diameter that may be too small for accurate
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
identification and quantitative analysis by optical microscopy copeial Convention, Inc. (USPC), Rockville, MD.
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D8489 − 23
count. Some certified reference materials (CRM) may include 12.2.1 Collect images on microbeads
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